Taku Mizuta

Parental care behavior in the monogamous, sexually dimorphic Madagascar paradise flycatcher: sex differences and the effect of brood size

I studied the parental care behavior of the Madagascar paradise flycatcher Terpsiphone mutata in northwestern Madagascar. I especially focused on feeding, brooding and vigilance behaviors. Feeding rate did not differ between males and females, but females spent more time at the nest than males. Females dedicated their time to brooding, while males perched on the nest and were vigilant. Both parents changed the feeding rate in relation to brood size, so the feeding rate per nestling was not different among nests of different brood size. Duration of brooding by females increased with decreasing brood size, suggesting that the Royama effect, the pattern of lower feeding rate per nestling in larger broods, did not apply in this study. Males spent more time on vigilance than females. Anti-predator vigilance by males should be important for nestling survival given the high predation pressure typical of this population. In conclusion, males provide considerable parental care probably to minimize nestling starvation and to avoid nest predation. My results are not consistent with the general pattern of less parental effort by males in monogamous, sexually dimorphic species.

Predation by Eulemur fulvus fulvus on a nestling of Terpsiphone mutata (Aves: Monarchidae) in dry forest in North-Western Madagascar.

The brown lemur Eulemur fulvus is the most widespread diurnal lemur species in Madagascar; it has six subspecies [1, 2]. All subspecies are medium-sized and live in groups. They feed predominantly on fruit, leaves, flowers and sap [1–3]. Generally, the diurnal prosimian species are thought to be plant eaters [4]. Some authors have reported that they also eat small vertebrates in captivity [4, 5]. In the wild, however, only one observation of meat-eating behaviour has ever been reported, that is the red-fronted lemur E. fulvus rufus preying on an infant of the ringtailed lemur Lemur catta [6]. This note reports the first observation of a diurnal lemur, the common brown lemur Eulemur fulvus fulvus, preying on a bird nestling in the wild.

Intrusion into neighboring home range by male Madagascar paradise flycatchers, Terpsiphone mutata: a circumstantial evidence for extra-pair copulation

Abstract The seasonal change in home range size and distribution of the male Madagascar paradise flycatcher, Terpsiphone mutata, was studied in deciduous dry forest of the Ampijoroa Forest Station, northwestern Madagascar. Male home ranges were spaced out in the prebreeding period but overlapped during the breeding period; this change resulted from male intrusion into neighboring home ranges. Male intrusion was often observed during the prelaying and laying stages of females in invaded home ranges. These stages are assumed to be in a fertile period of females. Intruder males tended to have longer tails as compared to resident males. Intruder males may be seeking extra-pair copulations. Females may prefer long-tailed males to short-tailed males as extra-pair partners, or long-tailed males may be dominant to short-tailed males.

Consequence of Inter Class Competition and Predation on the Adaptive Radiation of Lizards and Birds in the Dry Forest of Western Madagascar

Abstract Species interactions among phylogenetically distant but ecologically related vertebrates were studied in a dry forest of western Madagascar to evaluate whether competition and predation between lizards and birds have reciprocally affected adaptive radiation in Madagascar. Of 49 terrestrial and diurnal birds regularly seen in the study forest, we identified six guilds as carnivore (5 spp.), omnivore (2 spp.), carnivore/insectivore (7 spp.), strict insectivore (15 spp.), insectivore/nectarivore (6 spp.), and frugivore (5 spp.). Twelve lizards species were classified as omnivore (1 sp.), strict insectivore (9 spp.), and insectivore with occasional frugivory and nectarivory (2 spp.). The most dominant guilds of the vertebrates in terms of biomass were folivorous/frugivorous parrots, doves, and lemurs (6.7 kg/ha), followed by insectivorous lizards (1.7 kg/ha) and insectivorous birds (0.8 kg/ha) in the Ampijoroa dry forest. Despite their lower biomass, insectivorous birds appeared to be competitively more advantageous than the lizards in terms of prey consumption speed (230 prey/ha/hr by birds vs. 35 prey/ha/hr by lizards). Insectivorous and carnivorous birds may have kept insectivorous lizards from radiating in various niches in Madagascar, and may have promoted a reclusive lifestyle in lizards.

Song-count surveys and population estimates reveal the recovery of the endangered Amami Thrush Zoothera dauma major , which is endemic to Amami-Oshima Island in south-western Japan

The Amami Thrush, Zoothera dauma major, is an endemic subspecies of the Eurasian Scaly Thrush that is distributed only on Amami-Oshima Island in south-western Japan. This bird was formerly considered to be a distinct species ( Z . major ) and was listed on the IUCN Red List as ‘Critically Endangered’ based on the small population size estimated in the early 2000s. To re-evaluate the conservation status of this bird, we estimated the number of singing males from song-count surveys conducted by an NPO with public participation from 2007 to 2013. An estimation that applied a distance sampling method revealed the number of singing males to be 945–1,858 up to 2012. A sudden increase in song counts was recorded in 2013, and the estimate increased to 2,512 in 2013. Based on the assumption that the sex ratio does not deviate from 1:1, simply doubling the number was considered to produce the estimated population size (number of males and females that are capable of breeding). The present study also confirmed that the Amami Thrush was more abundant in older forest with less open habitat, suggesting that forest maturity is an important factor for thrush abundance. The relative density of the invasive small Indian mongoose Herpestes auropunctatus probably affected thrush abundance before the early 2010s prior to mongoose eradication efforts. Our results suggest that thrush recovery was likely associated with forest regeneration and mongoose eradication. However, it is important to continue population monitoring approaches including public participation to promote further conservation of the Amami Thrush.